Step-oblique mammography is an accurate technique for determining whether a mammographic finding visible on multiple images on only one projection (but not elucidated using standard additional mammographic projections) represents a summation artifact or a true mass and for precisely localizing the true mass for further evaluation.
The step-oblique mammography technique is an effective tool in the evaluation of patients who have densities visible just on one view. Projections are obtained every 15 degrees beginning with the view in which the density is visible. If the density still isn't visible with this technique, it can be considered a summation artifact, and no further evaluation is needed.
The diagnostic accuracy of step-oblique mammography will be maximized by carefully observing technical requirements.
- all step-oblique images should be taken with the breast in the same orientation (i.e., all mediolateral oblique or all lateromedial oblique)
- the nipple should be in profile on all step-oblique exposures and there should be no rolling of the breast .
- the patient should stand up straight during all step-oblique exposures.
- projections are obtained every 15 degrees beginning with the view in which the density is visible
- frequently used to assess the noncalcified density identified on only one standard mammographic projection
- helpful in evaluating grouped microcalcifications seen on only one standard view.
- helped in establishing the presence of truly clustered calcific particles
- permitted accurate three-dimensional localization of the lesion.
- step-oblique mammography also is useful in indicating the three-dimensional locations of more than one lesion in the same breast, especially if two or more lesions display similar mammographic features and are similar in distance from the nipple. Confirmation of the precise three-dimensional location of each lesion by step-oblique mammography permits planning of the optimal approach for imaging-guided biopsy.
- If the density isn't visible with this technique, it can be considered a summation artifact, and no further evaluation is needed.
It was initially described by K L Pearson et.al
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